1. Field of the Invention
The present invention relates to an organic semiconductor material, an organic semiconductor structure and an organic semiconductor device, wherein the organic semiconductor material exhibiting liquid crystal phase at wide temperature range, including at least ordinary temperature.
2. Description of the Related Art
In recent years, study about an organic semiconductor structure using an organic semiconductor material attracts attention, and its application to various devices is expected. As such application, a thin-film transistor (also called organic TFT) usable for a flexible display and the like, a light emitting element, solar battery and the like are being studied.
For the organic semiconductor structure, to be used at practical level, it is required to exhibit high charge carrier mobility at wide using temperature range. Also, preparation of a flexible molecular alignment film, which is uniform over a large area, is required. Therefore, it is desirable that the organic semiconductor structure exhibits liquid crystal phase at wide using temperature range (around −40 to +90° C.) including ordinary temperature, and that the liquid crystal phase has high charge carrier mobility.
Conventionally, for example, it has been reported that a rod-shaped liquid crystal material, such as a phenyl benzothiazole derivative, shows high charge carrier mobility in a liquid crystal state (for example, see M. Funahashi and J. Hanna, Jpn. J. Appl. Phys., 35, L703-L705 (1996)). Although this liquid crystal material shows liquid crystallinity at relatively high temperatures, this dose not show liquid crystallinity at wide using temperature range (around −40 to +90° C.) including ordinary temperature.